With the increasing popularity of radio communication systems, there are a variety of radio communication devices that are vastly available today, which includes cellular phones, wireless phones, wireless communication PC cards, small radio apparatuses and mobile radio devices. Consequently, the technique for forming an antenna inside the shell of those radio communication devices can be very important, especially for small radio apparatuses. Moreover, for achieving smaller, lighter and thinner radio communication devices, a technology for forming printed antennas on circuitboard had been developed.
In addition, for preventing electro magnetic interfere, it is common to form a shielding on a circuitboard for insulating the circuitboard from being adversely affected by magnetic waves so that the performance of the circuitboard can be ensured and enhanced. However, the shielding can also have an adverse effect upon the radiation intensity of the antenna.
Therefore, it is in need of an innovated and improved antenna structure configured to RF shieldings that can perform at high efficiency without being affected by electro magnetic interfere.